MODELING DISSOLUTION AND VOLATILIZATION OF LNAPL SOURCES MIGRATING ON THE GROUNDWATER TABLE

Schematic illustration of LNAPL migration and contamination of the subsurface. Description of a mathematical model describing LNAPL movement within a porous medium. Equations of the transport of LNAPL on groundwater table , of contaminant dissolved and by volatilising in the unsaturated zone. Quantification of mass fluxes at surface boundaries. The numerical solution uses alternate direction implicit scheme of finite-difference method for the solving of the two-dimensional governing equations. Comparison of model results obtain with different simulation conditions and parameter values. NAPL distribution in different phases with and without volatilisation. Effects of capillary fringe thickness on dissolution and of unsaturated zone depth on volatilisation. Simulated example of dissolved benzebne plume and field data measured 20 years after the spill.